Tuesday, November 18, 2008

Ruby(2)

Birthplaces of fine rubies

Which is the most beautiful ruby-red? Good question. The red of a ruby may involve very different nuances depending on its origin. The range of those nuances is quite wide, and could perhaps be compared to hotel categories, from luxury accommodation down to a plain inn or hostel. For example, if the gemstone experts refer to a 'Burmese ruby', they are talking about the top luxury category. However, it does not necessarily follow that the stone is of Burmese origin. It is basically an indication of the fact that the colour of the ruby in question is that typically shown by stones from the famous deposits in Burma (now Myanmar): a rich, full red with a slightly bluish hue. The colour is sometimes referred to as 'pigeon-blood-red', but the term 'Burmese colour' is a more fitting description. A connoisseur will immediately associate this colour with the legendary 'Mogok Stone Tract' and the gemstone centre of Mogok in the North of Myanmar. Here, the country's famous ruby deposits lie in a mountain valley surrounded by high peaks. Painstakingly, gemstones of an irresistible luminosity are brought to light in the 'valley of the rubies'. Unfortunately, really fine qualities are quite rare even here. The colour of a Burmese ruby is regarded as exceptionally vivid. It is said to display its unique brilliance in any light, be it natural or artificial.

The journey to the world's most important ruby deposits takes us further on to the small town of Mong Hsu in the North-East of Myanmar, where the most important ruby deposits of the nineties lie. Originally, it was believed that these rubies would hardly prove suitable for use in jewellery, since untreated Mong Hsu ruby crystals actually display two colours: a purple to black core and a bright red periphery. Only when it had been discovered that the dark core could be turned into deep red by means of heat treatment did rubies from Mong Hsu begin to find their way on to the jewellery market. Today, the Mong Hsu gemstone mines are still among the most important ruby suppliers. In the main, they offer heat-treated rubies in commercial qualities and sizes between 0.5 and 3 carats.

Ruby deposits also exist in neighbouring Vietnam, near the Chinese border. Rubies of Vietnamese origin generally display a slightly purplish hue. Rubies from Thailand, another classical supplier, however, often have a darker red which tends towards brown. This 'Siamese colour' - an elegantly muted deep red - is considered second in beauty only to the Burmese colour, and is especially popular in the USA. Ceylon rubies, which have now become very rare, are mainly light red, like ripe raspberries.

Other ruby deposits are located in Northern Pakistan in the Hunza Valley, Kashmir, Tadzhikistan, Laos, Nepal, and Afghanistan. But rubies are also produced in India, where deposits with relatively large crystals were discovered in the federal states of Mysore and Orissa. These crystals have many inclusions, but they are, nevertheless, eminently suited to being cut as beads or cabochons.

Lately, people have begun to talk about East Africa as a source of rubies. Straight after their discovery in the 1960s, rubies from Kenya and Tanzania surprised the experts by their beautiful, strong colour, which may vary from light to dark red. But in the African mines too, fine and clear rubies of good colour, purity and size are very rare. Usually the qualities mined are of a merely average quality.

Colour above (almost) everything

As we have said, colour is a ruby's most important feature. Its transparency is only of secondary importance. So inclusions do not impair the quality of a ruby unless they decrease the transparency of the stone or are located right in the centre of its table. On the contrary: inclusions within a ruby could be said to be its 'fingerprint', a statement of its individuality and, at the same time, proof of its genuineness and natural origin. The cut is essential: only a perfect cut will underline the beauty of this valuable and precious stone in a way befitting the 'king of the gemstones'. However, a really perfect ruby is as rare as perfect love. If you do come across it, it will cost a small fortune. But when you have found 'your' ruby, don't hesitate: hang on to it!

Data from:http://www.gemstone.org

Ruby



Ruby

Which colour would you spontaneously associate with love and vivacity, passion and power? It's obvious, isn't it? Red. Red is the colour of love. It radiates warmth and a strong sense of vitality. And red is also the colour of the ruby, the king of the gemstones. In the fascinating world of gemstones, the ruby is the undisputed ruler.

For thousands of years, the ruby has been considered one of the most valuable gemstones on Earth. It has everything a precious stone should have: magnificent colour, excellent hardness and outstanding brilliance. In addition to that, it is an extremely rare gemstone, especially in its finer qualities.

For a long time India was regarded as the ruby's classical country of origin. In the major works of Indian literature, a rich store of knowledge about gemstones has been handed down over a period of more than two thousand years. The term 'corundum', which we use today, is derived from the Sanskrit word 'kuruvinda'. The Sanskrit word for ruby is 'ratnaraj', which means something like 'king of the gemstones'. And it was a royal welcome indeed which used to be prepared for it. Whenever a particularly beautiful ruby crystal was found, the ruler sent high dignitaries out to meet the precious gemstone and welcome it in appropriate style. Today, rubies still decorate the insignia of many royal households. But are they really all genuine rubies? Read on to find out more!
!
Only a little bit of chrome ...

Ruby is the red variety of the mineral corundum, one of the hardest minerals on Earth, of which the sapphire is also a variety. Pure corundum is colourless. Slight traces of elements such as chrome, iron, titanium or vanadium are responsible for the colour. These gemstones have excellent hardness. On the Mohs scale their score of 9 is second only to that of the diamond. Only red corundum is entitled to be called ruby, all other colours being classified as sapphires. The close relationship between the ruby and the sapphire has only been known since the beginning of the 19th century. Up to that time, red garnets or spinels were also thought to be rubies. (That, indeed, is why the 'Black Ruby' and the 'Timur Ruby', two of the British Crown Jewels, were so named, when they are not actually rubies at all, but spinels.)

Ruby, this magnificent red variety from the multi-coloured corundum family, consists of aluminium oxide and chrome as well as very fine traces of other elements - depending on which deposit it was from. In really fine colours and good clarity, however, this gemstone occurs only very rarely in the world's mines. Somewhat paradoxically, it is actually the colouring element chrome which is responsible for this scarcity. True enough, millions of years ago, when the gemstones were being created deep inside the core of the Earth, chrome was the element which gave the ruby its wonderful colour. But at the same time it was also responsible for causing a multitude of fissures and cracks inside the crystals. Thus only very few ruby crystals were given the good conditions in which they could grow undisturbed to considerable sizes and crystallise to form perfect gemstones. For this reason, rubies of more than 3 carats in size are very rare. So it is no wonder that rubies with hardly any inclusions are so valuable that in good colours and larger sizes they achieve top prices at auctions, surpassing even those paid for diamonds in the same category.

Some rubies display a wonderful silky shine, the so-called 'silk' of the ruby. This phenomenon is caused by very fine needles of rutile. And now and then one of the rare star rubies is found. Here too, the mineral rutile is involved: having formed a star-shaped deposit within the ruby, it causes a captivating light effect known by the experts as asterism. If rubies of this kind are cut as half-dome shaped cabochons, the result is a six-spoked star which seems to glide magically across the surface of the stone when the latter is moved. Star rubies are precious rarities. Their value depends on the beauty and attractiveness of the colour and, though only to a lesser extent, on their transparency. Fine star rubies, however, should always display rays which are fully formed all the way to the imaginary horizontal line which runs through the middle of the stone, and the star itself should be situated right in the centre.

Ruby-red means passion

Red for ruby. Ruby-red. The most important thing about this precious stone is its colour. It was not for no reason that the name 'ruby' was derived from the Latin word 'rubens', meaning 'red'. The red of the ruby is incomparable: warm and fiery. Two magical elements are associated with the symbolism of this colour: fire and blood, implying warmth and life for mankind. So ruby-red is not just any old colour, no, it is absolutely undiluted, hot, passionate, powerful colour. Like no other gemstone, the ruby is the perfect way to express powerful feelings. Instead of symbolising a calm, controlled affection, a ring set with a precious ruby bears witness to that passionate, unbridled love that people can feel for each other.

Data from:http://www.gemstone.org

Saturday, August 30, 2008

Emerald(2)

Fingerprints of nature

The lively luminosity of its colour makes the emerald a unique gemstone. However, really good quality is fairly rare, with inclusions often marring the evenness of the colour – signs of the turbulent genesis which has characterised this gemstone. Fine inclusions, however, do not by any means diminish the high regard in which it is held. On the contrary: even with inclusions, an emerald in a deep, lively green still has a much higher value than an almost flawless emerald whose colour is paler. Affectionately, and rather poetically, the specialists call the numerous crystal inclusions, cracks or fissures which are typical of this gemstone 'jardin'. They regard the tender little green plants in the emerald garden as features of the identity of a gem which has grown naturally


So where do they come from and how is it that they exist at all? In order to answer these questions, we need to look far, far back into the time of the emerald's origin. Emeralds from Zimbabwe are among the oldest gemstones anywhere in the world. They were already growing 2600 million years ago, whilst some specimens from Pakistan, for example, are a mere 9 million years young. From a chemical-mineralogical point of view, emeralds are beryllium-aluminium-silicates with a good hardness of 7.5 to 8, and belong, like the light blue aquamarine, the tender pink morganite, the golden heliodor and the pale green beryl, to the large gemstone family of the beryls. Pure beryl is colourless. The colours do not occur until traces of some other element are added. In the case of the emerald, it is mainly traces of chromium and vanadium which are responsible for the fascinating colour. Normally, these elements are concentrated in quite different parts of the Earth's crust to beryllium, so the emerald should, strictly speaking, perhaps not exist at all. But during intensive tectonic processes such as orogenesis, metamorphism, emergences and erosion of the land, these contrasting elements found each other and crystallised out to make one of our most beautiful gemstones. The tension involved in the geological conditions conducive to the above processes produced some minor flaws, and some major ones. A glance through the magnifying-glass or microscope into the interior of an emerald tells us something about the eventful genesis of this unique gem: here we see small or large fissures; here the sparkle of a mini-crystal or a small bubble; here shapes of all kinds. While the crystals were still growing, some of these manifestations had the chance to 'heal', and thus the jagged three-phase inclusions typical of Colombian emeralds were formed: cavities filled with fluid, which often also contain a small bubble of gas and some tiny crystals. Logically enough, a genesis as turbulent as that of the emerald impedes the undisturbed formation of large, flawless crystals.


For this reason, it is only seldom that a large emerald with good colour and good transparency is found. That is why fine emeralds are so valuable. But for the very reason that the emerald has such a stormy past, it is surely entitled to show it - that is, as long as only a fine jardin is to be seen, and not a rank garden which spoils both colour and transparency.

The world of fine emeralds

Colombia continues to be at the top of the list in terms of the countries in which fine emeralds are found. It has about 150 known deposits, though not all of these are currently being exploited. The best known names are Muzo and Chivor, where emeralds were mined by the Incas in pre-Columbian times. In economic terms, the most important mine is at Coscuez, where some 60 faces are being worked. According to estimates, approximately three quarters of Colombia's emerald production now comes from the Coscuez Mine. Colombian emeralds differ from emeralds from other deposits in that they have an especially fine, shining emerald green unimpaired by any kind of bluish tint. The colour may vary slightly from find to find. This fascinatingly beautiful colour is so highly esteemed in the international emerald trade that even obvious inclusions are regarded as acceptable. But Colombia has yet more to offer: now and then the Colombian emerald mines throw up rarities such as Trapiche emeralds with their six rays emanating from the centre which resemble the spokes of a millwheel.
Even if many of the best emeralds are undisputedly of Colombian origin, the 'birthplace' of a stone is never an absolute guarantee of its immaculate quality. Fine emeralds are also found in other countries, such as Zambia, Brazil, Zimbabwe, Madagascar, Pakistan, India, Afghanistan and Russia. Zambia, Zimbabwe and Brazil in particular have a good reputation for fine emeralds in the international trade. Excellent emerald crystals in a beautiful, deep emerald green and with good transparency come from Zambia. Their colour is mostly darker than that of Colombian emeralds and often has a fine, slightly bluish undertone. Emeralds which are mostly smaller, but very fine, in a vivacious, intense green come from Zimbabwe's famous Sandawana Mine, and they often have a delicate yellowish-green nuance. And the famous emerald mines of Colombia currently face competition from right next door: Brazil's gemstone mine Nova Era also produces emeralds in beautiful green tones, and if they are less attractive than those of their famous neighbour it is only by a small margin. Brazil also supplies rare emerald cat's eyes and extremely rare emeralds with a six-spoked star. Thanks to the finds in Africa and Brazil, there are more emeralds on the market now than there used to be - to the delight of emerald enthusiasts .
A sophisticated gemston
eWhilst its good hardness protects the emerald to a large extent from scratches, its brittleness and its many fissures can make cutting, setting and cleaning rather difficult. Even for a skilled gem cutter, cutting emeralds presents a special challenge, firstly because of the high value of the raw crystals, and secondly because of the frequent inclusions. However, this does not detract from the cutters' love of this unique gem. Indeed, they have developed a special cut just for this gem: the emerald cut. The clear design of this rectangular or square cut with its bevelled corners brings out the beauty of this valuable gemstone to the full, at the same time protecting it from mechanical strain. Emeralds are also cut in many other, mainly classical shapes, but if the raw material contains a large number of inclusions, it may often be cut into a gently rounded cabochon, or into one of the emerald beads which are so popular in India.Today, many emeralds are enhanced with colourless oils or resins. This is a general trade practice, but it does have the consequence that these green treasures react very sensitively to inappropriate treatment. For example, they cannot be cleaned in an ultrasonic bath. The substances that may have been used by the cutter during his work, or applied subsequently, seal the fine pores in the surface of the gem. Removing them will end up giving the stone a matt appearance. For this reason, emerald rings should always be taken off before the wearer puts his or her hands in water containing cleansing agent.
A matter of trust
Unfortunately, because the emerald is not only one of the most beautiful gemstones, but also one of the most valuable, there are innumerable synthetics and imitations. So how can you protect yourself from these 'fakes'? Well, the best way is to buy from a specialist in whom you have confidence.
Large emeralds in particular should only be purchased with a report from a reputable gemmological institute. Such an institute will be able, thanks to the most modern examination techniques, to differentiate reliably between natural and synthetic emeralds, and will inform you as to whether the stone has undergone any treatment of the kind a purchaser has the right to know about.And one more piece of advice on the purchase of an emerald: whilst diamonds generously scintillate their fire in sizes below 1 carat, you should go for larger dimensions when acquiring a coloured gemstone. True, there are some lovely pieces of jewellery with small coloured gems to set decorative accents, but emeralds, like other coloured gemstones, do not really begin to show that beautiful glow below a certain size. How large 'your' emerald ends up will depend on your personal taste, and on your budget. Really large specimens of top quality are rare. This means that the price of a top-quality emerald may be higher than that of a diamond of the same weight. The fascination exuded by a fine emerald is simply unique.

Emerald


Emerald
Emeralds are fascinating gemstones. They have the most beautiful, most intense and most radiant green that can possibly be imagined: emerald green. Inclusions are tolerated. In top quality, fine emeralds are even more valuable than diamonds.
The name emerald comes from the Greek 'smaragdos' via the Old French 'esmeralde', and really just means 'green gemstone'. Innumerable fantastic stories have grown up around this magnificent gem. The Incas and Aztecs of South America, where the best emeralds are still found today, regarded the emerald as a holy gemstone. However, probably the oldest known finds were once made near the Red Sea in Egypt. Having said that, these gemstone mines, already exploited by Egyptian pharaohs between 3000 and 1500 B.C. and later referred to as 'Cleopatra's Mines', had already been exhausted by the time they were rediscovered in the early 19th century.

Written many centuries ago, the Vedas, the holy scriptures of the Indians, say of the precious green gems and their healing properties: 'Emeralds promise good luck ...'; and 'The emerald enhances the well-being ...'. So it was no wonder that the treasure chests of Indian maharajas and maharanis contained wonderful emeralds. One of the world's largest is the so-called 'Mogul Emerald'. It dates from 1695, weighs 217.80 carats, and is some 10cm tall. One side of it is inscribed with prayer texts, and engraved on the other there are magnificent floral ornaments. This legendary emerald was auctioned by Christie's of London to an unidentified buyer for 2.2m US Dollars on September 28th 2001.

Emeralds have been held in high esteem since ancient times. For that reason, some of the most famous emeralds are to be seen in museums and collections. The New York Museum of Natural History, for example, has an exhibit in which a cup made of pure emerald which belonged to the Emperor Jehangir is shown next to the 'Patricia', one of the largest Colombian emerald crystals, which weighs 632 carats. The collection of the Bank of Bogota includes five valuable emerald crystals with weights of between 220 and 1796 carats, and splendid emeralds also form part of the Iranian National Treasury, adorning, for example, the diadem of the former Empress Farah. The Turkish sultans also loved emeralds. In Istanbul's Topkapi Palace there are exhibits with items of jewellery, writing-implements and daggers, each lavishly adorned with emeralds and other gems.

The green of life and of love

The green of the emerald is the colour of life and of the springtime, which comes round again and again. But it has also, for centuries, been the colour of beauty and of constant love. In ancient Rome, green was the colour of Venus, the goddess of beauty and love. And today, this colour still occupies a special position in many cultures and religions. Green, for example, is the holy colour of Islam. Many of the states of the Arab League have green in their flags as a symbol of the unity of their faith. Yet this colour has a high status in the Catholic Church too, where green is regarded as the most natural and the most elemental of the liturgical colours.

The magnificent green of the emerald is a colour which conveys harmony, love of Nature and elemental joie de vivre. The human eye can never see enough of this unique colour. Pliny commented that green gladdened the eye without tiring it. Green is perceived as fresh and vivid, never as monotonous. And in view of the fact that this colour always changes somewhat between the bright light of day and the artificial light of a lamp, emerald green retains its lively vigour in all its nuances.

thank you for data :http://www.gemstone.org

10k Yellow Gold Pear-Shaped Peridot and Diamond Dangle Earrings


10k Yellow Gold Pear-Shaped Peridot and Diamond Dangle Earrings

Product Specifications
Jewelry Information:
Brand Name:Amazon.com Collection
Metal stamp:10k
Metal:yellow-gold
Material Type:peridot, diamond
Gem Type:Diamond, Peridot
Minimum total gem weight:3.04 carats
Setting:prong setting
Height:15.37 millimeters
Width:6.58 millimeters
Back finding:friction-back
Total metal weight:1.8 Grams
Number of stones:6

Diamond Information
Stone shape:round-peridot;pear-peridot;round-dia
Cut:good-cut

Peridot Information
Stone shape:round-peridot;pear-peridot;round-dia
Cut:good-cut